Flux Directing, Pole Span Setting, Feature on Rotor Lamination of Air-Cooled Electric Motor/Generator

Abstract

A rotor having a plurality of laminations joined together and mountable on a shaft for rotation relative to a stator of a rotary electric machine arrangement has a solid section that surrounds an opening within which the shaft is receivable. The solid section includes an outside diameter, magnet receiving voids, and steps delimiting a plurality of pole spans from flux directing features at sides of each of the pole spans. Adjacent flux directing features between adjacent pole spans are disposed on opposite sides of scalloped areas or other such recesses, permitting cooling air flow past the rotor. The invention also concerns a lamination usable together with additional laminations to provide such a rotor, as well as an arrangement, such as an AC motor, generator, or motor/generator, including a stator and such a rotor.

1 . A rotor having a plurality of laminations joined together and mountable on a shaft for rotation relative to a stator of a rotary electric machine arrangement, comprising:
 a solid section surrounding an opening within which the shaft is receivable, the solid section including an outside diameter, magnet receiving voids, and steps delimiting a plurality of pole spans from flux directing features at sides of each of the pole spans,   wherein adjacent flux directing features between adjacent pole spans are disposed on opposite sides of recesses permitting cooling air flow past the rotor.   
     
     
         2 . The rotor of  claim 1 , wherein each of the recesses permitting cooling air flow defines a scalloped area in the solid section. 
     
     
         3 . The rotor of  claim 1 , wherein the solid section defines a plurality of rotor poles. 
     
     
         4 . The rotor of  claim 3 , wherein each of the rotor poles includes a pair of said flux directing features, a single pole span between the flux directing features, and one of the steps located between each of the flux directing features and the single pole span. 
     
     
         5 . The rotor of  claim 3 , wherein each of said rotor poles includes a pair of the magnet receiving voids, and each of the steps is disposed directly over one of the magnet receiving voids. 
     
     
         6 . The rotor of  claim 1 , wherein the flux directing features permit air flow past the rotor between the recesses and the pole spans. 
     
     
         7 . The rotor of  claim 1 , wherein selection of the pole spans is made based on at least one of a maximum internal generator voltage, a minimum phase inductance, and a minimum generator reactance. 
     
     
         8 . The rotor of  claim 1 , wherein the rotor includes four rotor poles that cooperate with a thirty six slot stator. 
     
     
         9 . The rotor of  claim 1 , wherein the pole spans, steps, and flux directing features provide an air gap of varying cross section between the rotor and a stator associated with the rotor. 
     
     
         10 . The rotor of  claim 9 , wherein the air gap is at a minimum between the pole spans and the stator. 
     
     
         11 . A lamination, usable together with additional laminations to provide a rotor arrangement mountable on a shaft for rotation relative to a stator of a rotary electric machine arrangement having a plurality of laminations joined together to form a multilayer laminated rotor, comprising:
 a solid section surrounding an opening within which the shaft is receivable, the solid section including an outside diameter, magnet receiving voids, and steps delimiting a plurality of pole spans from flux directing features at sides of each of the pole spans,   wherein adjacent flux directing features between adjacent pole spans are disposed on opposite sides of recesses to permit cooling air flow.   
     
     
         12 . The lamination of  claim 11 , wherein each of the recesses to permit cooling air flow defines a scalloped area in the solid section. 
     
     
         13 . A rotary electric machine arrangement including a stator and a rotor having a plurality of laminations joined together and mountable on a shaft for rotation relative to the stator, comprising:
 a solid section surrounding an opening within which the shaft is receivable, the solid section including an outside diameter, magnet receiving voids, and steps delimiting a plurality of pole spans from flux directing features at sides of each of the pole spans,   wherein adjacent flux directing features between adjacent pole spans are disposed on opposite sides of recesses permitting cooling air flow past the rotor.   
     
     
         14 . The arrangement of  claim 13 , wherein each of the recesses permitting cooling air flow defines a scalloped area in the solid section. 
     
     
         15 . The arrangement of  claim 13 , wherein the solid section defines a plurality of rotor poles. 
     
     
         16 . The arrangement of  claim 15 , wherein each of the rotor poles includes a pair of said flux directing features, a single pole span between the flux directing features, and one of the steps located between each of the flux directing features and the single pole span. 
     
     
         17 . The arrangement of  claim 15 , wherein each of said rotor poles includes a pair of the magnet receiving voids, and each of the steps is disposed directly over one of the magnet receiving voids. 
     
     
         18 . The arrangement of  claim 13 , wherein the flux directing features permit air flow past the rotor between the recesses and the pole spans. 
     
     
         19 . The arrangement of  claim 13 , wherein selection of the pole spans is made based on at least one of a maximum internal generator voltage, a minimum phase inductance, and a minimum generator reactance. 
     
     
         20 . The arrangement of  claim 13 , wherein the rotor includes four rotor poles that cooperate with a thirty six slot stator.